Telephone cord connector



March 2, 1943. E. s. M LARN TELEPHONE CORD CONNECTOR Filed July '7, 1942 N TQ M M 0 m n 51 Patented Mar. 2, 1943 UNE'E'ED STATE TELEPHONE CORD CONNECTOR Application July 7, 1942, Serial No. 450,027

4 Claims. (c1. ire-34c) This invention relates to a telephone cord connector and more particularly to an arrangement of connecting flexible telephone cords of the tinsel type to telephon subset equipment.

An object of the invention is the provision of a simple andinexpensive cord connector by which either tipped or untipped cords may be connected quickly and easily to the same set of circuit terminals.

Another object is the provision of a connecting terminal arrangement normally adapted for use with tipped cords, which can be converted quickly for use with untipped cords by means of a clamping block of novel construction.

In applicants Patents No. 2,226,733 and No. 2,226,734 both issued on December 31, 1940, connecting block arrangements are disclosed for use with untipped telephone cords wherein the base member of a connecting block is provided with terminals havin projecting prongs or tines for penetrating the insulation of a flexible conductor when the latter is forced against the tines by a clamping member. The present invention is an improvement over the cord connecting devices disclosed in these patents and other similar known connectors in that it is of simpler construction, occupies less space, and has greater utility.

Other objects of the invention will appear in the following description given with the aid of the accompanying drawing, of which Figure 1 shows a plan View of a connector according to the invention,

Figures .2 and 3 are vertical sections, taken respectively through 22 and 33 of Figure 1,

Figure 4 shows part of the connector base, including the recess for a cord,

Figure 5 shows the connector block as used with tipped cords.

The invention is shown considerably enlarged in the drawing for the sake of clearness.

Referring to Figures 1 and 2, reference character I0 indicates a portion of a base of a telephone instrument made of molded insulating material. Near one edge, the base i formed with a raised portion 1! to provide an area of increased thickness. The part H in the present embodiment, is triangular in shape and near each corner thereof is a hollow threaded bushing 52 formed with a lug l3 extending below the under surface of the base to which appropriate subset circuits are connected. The threaded members are set in the base during the molding process.

A recess M is formed in part i I of the base for l the purpose of receiving the insulated end section of a length of telephone cord l5 which may be of the kind described in the. abovementioned patents. The outer part of recess M has a depending section lfi which cooperates withai complementary part of a clamping block of novel construction now aboutto be described.

When untipped'cord is to be used, a: clamping block 26 of novel: construction is provided for gripping the cord and retaining: ity in position. in the recess, as well as establishing connections between the cord conductors: and bushings I2,

Clamping member 26', as shown in Figures 1 to 3,. comprises a.- triangular plate which is secured by screws 22', 23 and 2A to. the threaded members t2 in base section H A-ridge. 25' depends. from the underside of plate 26 and fits into recess I4. Part of the ridge projects beyond the triangular plate and extends along recess l4 substantially to the edge of the base, and at 26, Figure 3, where it overlies the slanting part it of the recess, the ridge is formed with a corresponding downward slanting surface which is preferably corrugated to provide an effective grip on the wire in the recess. The clamping member is provided in the present embodiment with three spaced contact members I, 2 and 3, preferably of a non-corrosive metal which are molded therein. A number of teeth or tines are provided on the under edge of each contact member.

The contact members are disposed in spaced relation to each other in the clamping member so that the teeth 4 of each member project below the ridge and are aligned over a conductor of the parallel conductor cord disposed in the recess, the teeth and the depending ridge being so proportioned that when screws 22 to 24 are tightened, the cord is clamped securely between the under surface 21 of ridge 25 and recess l t, the teeth penetrating the insulation of the cord and extending into the conductors thereof.

The upper part of the respective contact members are formed into lugs having eyelets 39 at the ends thereof, and are bent over at 3i so that each eyelet is coaxially disposed in respect to a hole 32 in the clamping member aligned to register with bushings l2. Depressions 33 are formed in the top of the olamping member overlying the eyelets so that the upper surface of the eyelets are free from insulating material so that effective contact can be made therewith by the under surface of the heads of screws 22 to, 24.

The clamping member is preferably molded in one piece. It can however, be formed in two sections, the lower, 20, having a flat top surface on which the respective eyelets and the turnedover parts 3| of the contact members rest; and an upper cap section 2| having an under surface provided with recesses closely fitting the transverse parts of the contact members, and having its edges shaped so that they clear the heads of screws 22 to 24 as shown in the drawing. Pins 36 and/or a suitable moisture proof cement may be used to secure the two parts 20 and El to each other.

The clamping member just described is preferably molded of a thermo setting plastic, although any plastic material with good insulating qualities and good resistance to heat deformation may be used.

In order that the conductor may always be placed right side up in the recess, a groove 34 is provided in the bottom of the recess to receive a bead formed on one side of the parallel cord.

If the connecting block is to be used with cords having tips 35, the clamping block is removed and the same screws maybe used to attach the cords as shown in Figure 5.

I claim:

1. In a connector of the type described, a clamping block, a plurality of contact members disposed side to side in spaced parallel relationship to each other in said block, insulation piercing teeth on each of said members, a screw individual to each contact member for holding said block in engagement with a parallel-conductor cord and for forcing the teeth of said contact member through the insulation of a conductor, and means comprising said screws for connecting circuits to said contact members.

2. In a connector of the type described, a base member provided with a recess for receiving the insulated end of a parallel-conductor cord, a plurality of threaded bushings molded into said base member, a circuit-connecting lug attached to each bushing means for connecting said bushings to a parallel-conductor cord in said recess comprising a clamping block provided with screw holes disposed so as to register with said bushings, a screw for each of said holes for securing said clamping block to said bushings, a ridge formed in said block adapted to fit into said recess, a plurality of contact members in said block in spaced relation to each other and disposed so that the lower edge of each contact member is aligned with a conductor of a parallel conductor cord in said recess, a plurality of teeth projecting from the lower edges of said contact members below the surface of said ridge, an eyelet formed in the upper part of each contact memher and disposed coaxially with one of the holes in said clamping block so as to be engaged by the screw therein, the arrangement being such that when said screws are tightened the cord is secured in said recess by said ridge and the teeth of each contact member are forced through the cord insulation into engagement with one of the conductors.

3. A connector according to claim 2 in which one of said bushings is locatedon each side of said recess and one just beyond the end of said recess.

4. A connector according to claim 2 wherein said clamping block may be removed and said screws used for connecting the tips of a tipped cord to said bushing.

ERNEST S. MCLARN. 

